In the construction and interior decorating industry, widespread use is made of drywall construction wherein interior area enclosure such as interior surface walls are usually formed by nailing or screwing drywall panels to frame members after which finishing is necessary. Such finishing involves covering of nail or screw heads and joins between drywall panels to provide a continuous smooth surface which does not show the joins or nail or screw heads. The surface must be free from both dents and bumps.
Drywall panels often have slightly recessed joining margins so that tape may be applied over joins without forming a ridge in the surface. However, frequently the panels must be cut to fit and these recessed margins may not be conveniently used. Thus a large amount of skilled labour is needed involving the application of tape and plaster over adjoining board joints, the plaster being applied in several layers with sanding between each layer. The process, in addition to requiring skilled labor is time consuming and generates quantities of fine chalk dust as a consequence of the necessary intervening sanding-down procedures. The dust itself constitutes a health hazard, as well as being a general nuisance. Fairly complex carpentry is required for door and window trim and for baseboard and cove.
Even when all the drywall is completed, finished and trimmed, it is necessary to apply paint and/or wall paper paint usually needs at least a subcoat and a finishing coat of paint and wall paper requires pasting (or wetting to activate pre-applied paste) and accurate cutting. Decorative paneling can be glued or nailed into place. Tiling requires application of adhesive and later grouting. The labour-intensive nature of all the necessary stages is self-evident, and well known.
In the case of floors, a subfloor, often of plywood is laid on the rough base and nailed down. Thereafter the application of vinyl, parquet floor or any other type of floor is again a skilled job.
In all cases a mistake, once made can only usually be corrected by use of a second finish sheet since the first is usually badly damaged and not reusable.